This invention relates to the production of item comprising accumulations of folded sheets, particularly mail pieces. More particularly, it relates to a mechanism for accumulating and folding sheets.
Self-mailers are mail pieces which are produced from pre-cut forms which are folded and sealed to form a mail piece, and are well known, as is apparatus for printing and forming such self-mailers. Commonly assigned, co-pending U.S. Application, Ser. No. 407,583, to: Samuel W. Martin, filed Sept. 14, 1989 (C-574) discloses one such self-mailer wherein a pre-cut form is printed on a laser printer, or similar computer output printer, and fed to a folding and sealing apparatus to produce a self-mailer. Similarly, U.S. Pat. No. 3,995,808 to: Kehoe, issued Sept. 7, 1976 discloses another self-mailer wherein a web of forms is printed, folded longitudinally and sealed, and separated to form individual self-mailers. U.S. Pat. No. 4,063,398 to: Huffman, issued: Dec. 20, 1977 discloses another self-mailer wherein a web of forms is folded transversely to produce self-mailers. Huffman also provides for insertion of preprinted pieces or "stuffers".
In general self-mailers as taught by the prior art are useful as a means of generating large numbers of mail pieces, but are limited in that they can be formed into only a small number of configurations. (By configurations, as applied to mail pieces herein, is meant variations such as use of a windowed or a printed envelope, variations in the number and type of printed pages, and variations in the number and type of pre-printed inserts.) At most, like Huffman they may provide for an ability to insert "stuffers". Further, with the exception of the above mentioned U.S. Application, Ser. No. 407,583 the equipment for producing such self-mailers has generally been physically large and suitable only for use in environments such as large computing centers.
Where it has been necessary to provide greater flexibility in the configuration of a mail piece which may be produced the solutions taught by the prior art have generally involved the use of inserters. An inserter is a transport system having a plurality of stations and along which a "control document" is transported from station to station. At selected stations pre-printed inserts maybe accumulated with the control document and at the last station the entire accumulation is inserted in a pre-formed envelope. A typical use of such inserter systems would be by a bank mailing monthly statements to its customers, where the control document would be individual statements printed on the bank mainframe computer and the inserts would include each individual's cancelled checks. Such inserter systems are described, for example, in U.S. Pat. No. 3,935,429; to: Braneky et al.; For: Process and Apparatus for Controlling Document Feeding Machines From Indicia Contained on a Document Fed Therefrom; issued: Jan. 27, 1976.
Inserters do provide a high degree of flexibility in producing mail pieces in a number of configurations, and have proven very satisfactory for users such as banks and credit card companies. However, they suffer also from major limitations. First, because inserter systems generally do not operate under the control of the computer which prints the control document, a very significant problem exists in assuring that the proper inserts are matched with the correct control document. Because of this difficulty it has generally been necessary to use window envelopes with inserter systems rather than printed envelopes, so that an address pre-printed on the control document could be used to deliver the mail piece. Finally, inserters, like equipment for producing self-mailers, are generally quite physically large and suitable for use only in a large computer operation or production mail room.
Another approach to the problem of producing mail pieces was developed by Pitney Bowes Inc., assignee of the subject invention, under contract with the U.S.P.S. This equipment, known as PPHE (for Printing and Paper Handling Equipment) printed a continuous web, collated and separated the web to form sheets, folded the collated sheets longitudinally, and wrapped an envelope form around the wrapped sheets. The PPHE had a capability to add "stuffers" to a mail piece and was intended for production applications only, as the equipment was tens of feet long. The PPHE lacked capability to print envelope forms or handle variable length sheets.
The major steps in forming a mail piece involve folding to an appropriate size an accumulation of the various elements of the mail piece, and enclosing the sheets comprised in the mail form within an envelope. This enclosing step has normally been carried out by inserter systems such as those discussed above, though systems such a the PPHE which wrap sheets in an envelope form are also known. In either case, however, prior art systems have generally provided separate mechanisms for folding operations and for accumulation operations, with the result that prior art systems have generally been large and expensive.
Typical of such systems are those shown in U.S. Pat. Nos. 4,014,535 to: Klied et al. and U.S. Pat. No. 4,022,457 to: Mavin et al., which disclose the accumulator and folder mechanisms for the PPHE, respectively. In U.S. Pat. No. 4,014,535 a rotating cylinder with its circumference equal to a predetermined sheet length is provided. A printed web is wrapped around the cylinder a predetermined number of times and the resulting spiral is cut with a single stroke to produce the desired number of sheets. U.S. Pat. No. 4,022,457 shows the `plow` folding mechanism which longitudinally folded the resulting accumulation. At least partly as a result of this approach systems such as the PPHE were large and expensive and not suited for an office environment.
Thus it is an object of the subject invention to provide a simple, and compact mechanism for accumulating and folding the elements of a mail piece.